The engine immobiliser system is designed to prevent the vehicle from being stolen. This system uses a transponder key ecu that stores the key codes of authorized ignition keys. If an attempt is made to start the engine using an unauthorized key, the ecu sends a signal to the ecm to prohibit fuel delivery and ignition, effectively disabling the engine.

The transponder key coil receives this signal, the transponder key amplifier amplifies it, and then the signal is transmitted to the ecu. The ecu matches the key's id code with the vehicle's id code, which was previously registered in the ecu and then communicates the results to the ecm using sfi communication.
Engine immobiliser system
How to proceed with troubleshootingEmission control system
Parts location
System diagram
On-vehicle inspection
Check fuel cut rpm
Increase the engine speed to at least 3,500 rpm.
Use a sound scope to check for injector operating
noise.
Check that the operating sounds stop momentarily
and then resume when the t ...
Transmitter id not registered in main mode
Description
Inspection procedure
Notice:
It is necessary to register an id code after replacing the tire pressure
warning valve and
transmitter and/or the tire pressure monitor ecu (see page tw-9).
Hint:
Set the tire pressure to the specified value.
Standard pressure:
220 kpa (2.2 ...
Diagnosis system
Description
The occupant classification ecu controls the functions of
the occupant classification system on the vehicle. Data
of the occupant classification system can be read in the
data link connector 3 (dlc3) of the vehicle. When the
system seems to be malfunctioning, use the intelligen ...